Field of the Invention
The present invention relates to an instrument for operating a fluid injector that uses a multi-microneedle device.
Discussion of the Background
Fluid injectors which use a multi-microneedle device are well known, for example, in the medical field. Such a fluid injector is known as a syringe in the medical field.
A fluid injector is provided with a fluid retention barrel (syringe barrel of a syringe) which includes a long fluid retention space that can retain a given amount of fluid (e.g., medicinal solution in the medical field), a fluid outlet nozzle which is arranged at an end in a longitudinal direction of the fluid retention space and able to discharge the fluid from the fluid retention space, and a fluid retention space inlet opening which is arranged at the other end in a longitudinal direction of the fluid retention space. The fluid injector is further provided with a piston member which is slidably assembled into the fluid retention space of the fluid retention barrel along a center line in the longitudinal direction via the fluid retention space inlet opening.
It is considered recently in the medical field to use a multi-microneedle device, in place of a single injection needle well known in the medical field, for conducting intradermal injection, with the device being mounted to the fluid outlet nozzle of the injection barrel of a conventional syringe. The multi-microneedle device is provided with a body that is formed with an outlet nozzle mounting nozzle which is detachably mounted to a fluid outlet nozzle of a syringe barrel to discharge a fluid (medicinal solution in the medical field), and a fluid retention space which temporarily retains the fluid that has been discharged to the outlet nozzle mounting nozzle from the fluid outlet nozzle of the syringe barrel by the pressing force of the piston member of the syringe. The multi-microneedle device is further provided with a plurality of microneedles which are arranged on a plane of the body, the plane being located on an opposite side of the outlet nozzle mounting nozzle, being intervened by the fluid retention space.
The plane of the body functions as a skin contact surface. Each of the plurality of microneedles has a microscopic fluid injection channel which is extended from a base end on the plane to a tip that is apart from the plane. In each of the plurality of the microneedles, the length between the base end and the tip (i.e. the height of each microneedle) is set so as to fall within a range of the thickness of a skin tissue, against which the microneedles are used, of an organism (e.g., any human being) possessing the skin tissue.